ZOJ 1494 爬虫爬井

#include<iostream>
using namespace std;

 

int main()
{
    int n,u,d;
    int min,dis;
    while(cin>>n>>u>>d && !(n==0&&u==0&&d==0))
    {
/*        min=n*2/(u-d);
        if(min*(u-d)/2+2*d-u>=n)
            cout<<int(min-3+0.9999)<<endl;
        else
            cout<<int(min-1+0.9999)<<endl;   */

        dis=0;
        min=0;
        dis+=u;
        min++;
        while(dis<n)
        {
            dis=dis-d+u;
            min+=2;
        }
        cout<<min<<endl;

    }
    return 0;
}